1. Field of the Invention
The present invention relates to a liquid crystal display (“LCD”) device, and more particularly, to a touch panel equipped LCD device. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for preventing light leakage by being provided with a built-in touch sensor and a gate shielding line.
2. Discussion of the Related Art
Generally, a touch panel is an input means, which is provided to an image display such as a cathode ray tube, an LCD, a field emission display, a plasma display panel, and an electroluminescence device, for inputting information in a manner that a user pressurizes a screen by contact force.
The touch panels are classified into a resistance film type and a capacitance type. In the resistance film type touch panel, when a voltage is applied between two opposing conductive layers, a user presses a screen to make the two conductive layers come into contact with each other. A voltage or current variation generated from the contact point is then detected to read a coordinate value of the contact point.
In the capacitance type touch panel, while capacitance charging or discharging iteratively keeps taking place on a transparent conductive film or glass, a small quantity of electric charges is accumulated between the conductive film and a stylus as a pen type input means. The electric charge quantity is detected from an input point to be converted into a coordinate value. Since the capacitance type touch panel is required to supply electricity to the stylus, an analog input resistance type touch panel, which is built in one body of a liquid crystal display panel among flat panel displays, is preferred.
However, light leakage occurs in the touch panel loaded LCD due to a lateral field generated between a gate line and a common electrode. Extending a masking dimension of a black matrix to solve the problem causes another problem, namely that transmissivity or an aperture ratio is reduced.